1. Field of the Invention
The present invention relates to an engine. More particularly, the present invention relates to an engine provided with connecting lines connecting each cylinder for improving intake efficiency.
2. Description of Related Art
Generally, at the state that an intake valve is opened and an exhaust valve is closed during intake stroke of a cylinder, pressure changes, formed by movement of a piston from a top dead center to a bottom dead center, induce air or air-fuel mixture to flow in the cylinder.
In compression stroke, the intake valve is closed, so that flowing of the air or air-mixture is blocked. This stagnant flowing induces pumping loss as well as intake loss.
Further, in an engine provided with a turbo-charger, air amount flowing into a cylinder is increased in acceleration state, and turbine rotation speed and compressor rotation speed are increased due to increase in combustion gas. Thus, engine output also is improved according to increase in charging air. However, time is required to change power output in response to a throttle change, so called as a Turbo Lag
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.